Polish rod packing



P. M. REA EIOLISH ROD PACKING Dec. 16, 1941;

Filed Nqv. 9, 1939 INVQENTOR ATTORNEY Patented Dec. 16, 1941 UNITED STATES PATENT OFFICE I POLISH ROD PACKING Philip Rea, Oklahoma City, Okla. Application November 9, 1939, Serial No. 303,588

Claims.

I vision of mating packing rubbers for side thrust polish rod packing glands, which include an improved mediumfor dressing rusted or pitted polish rods, the medium being so arranged that there is no undue friction between it and the rod.

In the above mentioned co-pending patent application, soft metal or lead bars are provided within the packer rubbers for contacting the polish rod, and any pits or irregularities in the rod are filled by particles of the lead which are scraped from the bars during reciprocation of the rod. 7

It has been discovered that, due to the nature of their materials, the bars and packer rubbers do not wear away evenly with each other under usage, the bars wearing away more quickly than the rubbers. It has also been discovered that in order to properly dress a pitted polish rod, very little pressure should be exerted in urging the lead bars into contact with the polish rod. Since a greater pressure is required upon the rubbers to effect a seal than is necessary upon the bars to treat the rod, it is imperative that the bar is relieved from receiving this excessive amount of pressure in order to accomplish a substantially equal speed of erosion.

' Attempt has been made to overcome this difliculty by the use of a body of lea-d woolin pockets in the rubbers, in lieu of the lead bars, but this has proven to be unsatisfactory, due to the fact that excessive quantities of the lead wool are dragged or pulled from the pockets by the pitted polish rod.

The present invention permits the use of a solid barof lead for treating thepolish rod, but also compensates for the difierencein the speed with which the bars and the rubbers are worn away by usage. This compensation is accomplished by forming each lead bar of two longitudinally tapered or bevelled sections which complementally fill a pocket in the packing rubbers. The sections are therefore permitted to slide longitudinally with relation to each other'as the rubber is fed toward the polish rod, and this slippage betweenthe sections prevents the bar from being forced into the rod at a pressure sufiicient to cause excessive heat. The slippage between the bar sections makes it possible for the bar to be urged toward the rod only by the frictional engagement of the 'enveloping'packing rubber, and consequently excessive pressure on the rod is eliminated.

A further object is the provision of a side thrustpacking gland for polish rods, in which the packing elements may be easily and quickly replaced when worn. I

Other objects of the invention will be apparent from the following description of the accompanying one-sheet drawing wherein:

Figure l is an elevational sectional View of a packing rubber and a lead bar insert made in accordance with the invention;

Figure 2 is a perspective view of one complete lead insert;

Figure 3 is a perspective View of one of the packer rubbers with the lead insert dotted in position within a pocket in the rubber;

Figure 4 is an elevational sectional view of a polish rod packing gland adapted to use the packing elements of the present invention; and,

Figure 5 is a fragmentary elevational sectional View of a slightly different embodiment of the invention. f Like characters of reference designate like parts in all of the figures.

In the drawing:

Figure 4 illustrates a side thrust polish rod packing gland or head including a lower body section I having a substantially rectangular packing chamber 2 for receiving two resilient packing elements 3 which embody the present invention and which are more fully described hereinbelow.

The body section I has a centrally located depending tubular nipple 4 adapted for threaded connection to the upper end of a string of production tubing 5. A polish rod 6 is reciprocatably journalled in a metal bearing sleeve I pressed into the nipple portion 4 of the body section I. The lower end of the polish rod 6 is adapted to be connected to a pump rod string, not shown, and its upper end connects to a suitable power unit, not shown, whereby'the polish rod may be reciprocated for imparting similar movement to the pump rod string for operating a pump at the lower end of the tubing string.

The reference numeral 8 indicates'an upper body section which fits upon the upper end of the body section l and closes the upper open end of the packing chamber 2. This upper body section 8 has a lubricating chamber 9 and thereabove a suitable packing gland Ill for sealing around the polish rod 6, and is held firmly upon,

the body section I by any suitable means such as bolts, not shown.

As is usual with side thrust polish rod packing heads, the body section I is equipped with two oppositely disposed thrust screws l I having their inner ends provided with thrust plates or followers E2. The thrust screws are rotatable within the followers which are of a size and shape to substantially fill the cross sectional area of the packing chamber 2. The thrust screws and followers are the means whereby the packing elements 3 are selectively urged toward the polish rod so as to accomplish a fluid tight seal therewith to prevent escape of fluid from the tubing string 5.

The present invention include the structural arrangement of the packing elements 3 and their allied or supported inserts, as well as the removable upper body section 8 whereby the packing rubbers may be replaced without removal or disconnection of the followers l2 and thrust screws ll.

Each of the resilient packing elements 3 is identical, and each consists substantally of a body of resilient material having a cross sectional area and shape equal substantially to that of the packing chamber 2 of the head. In the drawing, the chamber 2 and packing elements 3 are illustrated as being substantially square in cross section, however, they could well be round, hexagonal, rectangular, and the like if desired.

One end of each packing element 3 is provided with an arcuate groove l3 which is formed on a radius equal substantially to the radius of the polish rod 6, so that when the two elements 3 have their grooved ends presented to the polish rod from opposite sides, they complementally surround the polish rod in contiguous proximity.

Each element 3 is provided with a longitudinally extending pocket or slot l4 preferably located centrally with relation to its upper and lower surfaces. Each pocket M is adapted to receive a soft metal, preferably lead, insert 15 which is best illustrated in Fig. 2.

The lead inserts l5 are each formed to substantially fill the pocket I4, and are each comprised of two sections I6 and I! having their adjacent ends tapered or bevelled identically as shown at E8. The section 16 has an arcuate end groove l9 similar in radius to the groove 13 in the packing element 3.

In Figs. 1, 3 and 4 the outer end of the insert section 5? is shown as extending through the element 3 to its outer end surface however, this outer end of the element 3 may, if desired, cover the end of the insert as is illustrated in Fig. 5 of the drawing.

In operation, as the sealing elements 3 and their lead inserts i5 are simultaneously urged toward the polish rod by the followers I2 and thrust screws H, the followers cannot positively force the insert sections l6 into violent engagement with the polish rod 6 due to the provision of the bevelled surfaces l8 of the insert sections l6 and IT. Pressure between the inner ends of the inserts i6 and surface of the polish rod 6 cannot become excessive, due to the fact that the ections It may slide outwardly upon the sections IT. This slippage is, of course, limited by the pressure with which the packing elements 3 are compressed within the packing chamber 2, but the resiliency of the rubber has been found to be sufficient to prevent excessive pressure between the polish rod and the inserts. The inserts are actually, in most instances moved toward the polish rod only by frictional engagement with the walls of the pockets M in the packing elements.

Practically all of the packing elements and inserts can be used up before the insert section I! is positively impinged between the follower and the polish rod.

By forming the body sections I and 8 in such a manner that they are separable from each other along a horizontal line of division, it has been made possible to replace the packing members by merely raising the body section 8 off the lower section, and lifting out the worn rubbers. Heretofore, it has been customary to provide removable plates at each end of the packer chamber, the plates carrying the thrust screws. That construction required the removal of both plates in order to get at the packing rubbers, and the rubbers then had to be gouged or hooked out of their chamber with some hand tool.

Obviously the invention is capable of embodiment in forms other than those specific to the drawing herein, and it is therefore not intended to confine the scope of the invention further than it is confined by the scope of the appended claims.

I claim:

1. The combination with a body of resilient packing for sealing around a reciprocatable hard metal element, of a pocket formed in the body and extending substantially perpendicular to the element; and, an insert of soft metal carried within the pocket with one end presented to the element, said insert composed of a'plurality of members longitudinally aligned with each other and having meeting surfaces extending in a plane lying at an acute angle with relation to the axes of the members, whereby the members may shift longitudinally with relation to each other under pressure exerted longitudinally of either.

2. The combination with a body of resilient packing for sealing against a reciprocatable hard metal element, of: a pocket formed in the body; and, an insert of soft metal carried within the pocket, said insert including a pair of members one of which is adapted to contact said element, and the other of which extends outwardly away from said element beyond the first member, said members having smooth meeting bevelled surfaces whereby one member may slide along the other when pressure is applied to either tending to move it toward or away from the reciprocatable element.

3. In a packing for sealing around a reciprocatable hard metal member, the combination of: a resilient body extending substantially perpendicular to'the member and adapted to beurged toward the member for effecting a seal therewith; a soft metal element carried by the 'body'with one'end contacting the member; said element being movable with said body only through action of its frictional engagement therewith, and being shiftable" with relation to the body under the exertion of" pressure sufiicient to overcome" the frictional engagement of the body, said element alsobeing composed of a plurality of longitudinally aligned members extending substantially perpendicular to the hard metal member and having meeting surfaces extending in a plane lying at an acute angle with relation to the common axesof the members, whereby the me mbers may shift longitudinally with relation to each,

other under the exertion of sufficient longitudinal pressure upon either.

4. In a packing for sealing around a reciprocatable hard metal member, the combination of: a resilient body extending substantially perpendicular to the member and adapted to be urged toward the member for effecting a seal therewith; a soft metal element carried by the body with one end contacting the member; said element being composed of a plurality of longitudinally aligned members extending substantially perpendicular to the hard metal member and having meeting surfaces extending in a plane lying at an acute angle with relation to the common axes of the members, whereby the members may shift longitudinally with relation to each other under the exertion of suificient longitudinal pressure upon either.

5. The combination with a body of resilient packing for sealing around a reciprocatable hard metal member, of a soft metal element carried by the body and extending substantially perpendicular to the hard metal member and having one end presented to said member, said soft metal element composed of a plurality of members longitudinally aligned with each other and having meeting surfaces extending in a plane lying at an acute angle with relation to the axes of the members, whereby they may shift longitudinally with relation to each other under pressure exerted longitudinally of either.

PHILIP M. REA. 

